In 1999, seventeen-year-old Tone Vaterland was killed on her way home from work. Desperate for a conviction the police deemed the investigation an open-and-shut case and sent her spurned boyfriend, Danny Momrak, down for murder. But twenty years later William Wisting receives a puzzling letter. It suggests the wrong man was convicted for Tone's death. And the real murderer is still out there. Wisting is quickly thrown into a terrifying race against time where he must find the sender, decipher this mysterious letter and catch the real killer - before they strike again . . .